190 RELATION BETWEEN CLIMATE AND VEGETATION 



on the top of a very hig'h mountain, in the midst of a thick forest, 

 the characteristic features of which are due to Bamboos and Tree 

 Ferns. 



In this canton the roads are everywhere far above deep valleys, 

 and the mountain sides, even the steepest, are, to a certain height, 

 covered with Coca plantations as far as the eye can reach. Indigo 

 occurs abundantly m all these places, and the forests are full 

 of curious and useful plants. I need only mention the Incienso, 

 a species of Clusia which discharges, when wounded, a pale- 

 yellow resin used for incense : the Matico {Piper matico), the 

 aromatic and astringent leaves of which have a great reputation 

 as vulneraries ; the Aristolochia, called Vejuco, discovered by 

 Haenke, who says it is an infallible cure for serpent-bites ; a 

 Myrica (Arbol de cera), from the fruits of which the inhabitants 

 of Yungas extract wax for candle-making ; lastly, the Cargua- 

 Cargua {Cascarilla magnifolid), or pseudo Quinquina, which is 

 generally at the bottom of the valleys, whilst the true Quinquina, 

 with bitter, febrifugal bark, is found in more elevated places. 



Leaving Chulumani I proceeded to Chirca and then to 

 Yanacache, situated in a romantic spot on the side of a Cordillera, 

 the snow-white crest of which rises almost perpendicularly above 

 the forest which more immediately surrounds the town. I then 

 passed on through Milluguaia to Coripata, from the environs of 

 which the best Coca in all Bolivia is obtained ; the road leading 

 from Coripata to Coroico pasf;es through magnificent plantations 

 of this valuable shrub. Between the town and river Coroico 

 the descent is very steep and frightfully rugged ; after passing 

 this the traveller comes to a magnificent road which takes hira 

 up to the regions of perpetual snow, and which had been, when 

 I was there, but lately thrown open to the public. It follows 

 the bed of the Coroico, and then goes through one of the most 

 broken countries it is possible to conceive. Often cut out of the 

 solid rock, it in many places has the appearance of being sus- 

 pended over tremendous precipices and of resting against the 

 almost vertical side of the mountain. Accustomed to the dan- 

 gerous paths of the southern Cordillera, I was surprised to find 

 myself moving with such ease in the midst of these abysses, which 

 I had now full leisure to contemplate. The mountain rises 

 everywhere straight up, and its damp sides are covered with a 

 veo-etation which, hanging down in festoons, often conceals 

 natural caverns ; below flows the Coroico along its rocky bed. 

 A thick fog hid the higher parts of this glorious scenery, and 

 into it I myself soon entered. 



The plants of this region are interesting in the highest degree. 

 I had in a very short time got beyond the Coca district, as the 

 Erythroxylon does not grow at a greater elevation than 



